... The calibration of astrophysical spectra in wavelength based on calibration lamp data suffers from different kinds of uncertainties. Besides inaccuracies in the observational phase, common data reduction practice adds ``pixelation'' errors, due to the fact that the centering method does not use the correct PSF. These model mismatch errors depend, for a given feature, on the sub-pixel location of the line center (David & Verschueren, private communication). ...

Subject of Celestial Mechanics. ... Differential Absolute Coordinates Equations of the Problem. ... General Integral of Non-Perturbed Motion. ... General Equation of Non-Perturbed Orbit. ... Other Integration Methods of Non-Perturbed Motion Differential Equations; Bine Equation for Case of Non-Perturbed Motion. ... Ellipsical Motion, Kepler Equation. ... Motion Differential Equations in Absolute Coordinates. ... Equation of System of Bodies Motion in Barycentric Coordinates, in Relative Coordinates. ...

T he Siding Spring Survey (SSS) is a Near-Earth Object search program that utilises the 0.5-m Uppsala Schmidt Telescope at Siding Spring Observatory, N.S.W., Australia. ... The mission of the Siding Spring Survey is to contribute to the inventory of near-earth objects (NEOs), or more specifically, the potentially hazardous asteroids (PHAs) and comets (PHOs) that may pose a threat of impact and thus harm to civilization. ... Based on the CSS Mission page . ... Siding Spring Survey Main Page . ...

The nasa.gov site requires that JavaScripts be enabled in your browser. ... Contact NASA . ... The term "astronaut" derives from the Greek words meaning "space sailor," and refers to all who have been launched as crew members aboard NASA spacecraft bound for orbit and beyond. Since the inception of NASA's human space flight program, we have also maintained the term "astronaut" as the title for those selected to join the NASA corps of astronauts who make "space sailing" their career profession. ...

... Bad Astronomy . ... Every few months, one of a series of questions comes up on the USENET group sci.astro involving tides, or the rotation of the Moon, or the recession of the Moon from the Earth. ... Why the Moon's rotation period is the same as the length of time it takes to orbit the Earth (same as number 1, but phrased differently). ... But when this happens, the time it takes for the Earth to rotate once will be slowed to exactly the same time it takes for the Moon to go around the Earth once! ...

USING THE CORRELATION BETWEEN ISGRI SURVEY RESULTS AND OTHER CATALOGUES TO AID SOURCE IDENTIFICATION John B. Stephen, A. Malizia and L. Bassani IASF-INAF, Via P. Gobetti 101, 40129 Bologna, ITALY, E-mail: stephen@iasfbo.inaf.it ABSTRACT In order to help in the identification of INTEGRAL/ISGRI sources, we have developed a software package which allows a rapid and detailed cross-correlation to be performed between various source catalogues. ... We show below some preliminary results from this analysis. ...